This invention relates generally to a light emitting device and, more specifically, to a device adapted to emit condensed light from a lamp, condensed fluorescent or phosphorescent light generated by irradiation with a lamp or a laser beam generated by excitation with a flash lamp.
Known devices for collecting light from a lamp on an optical material include (a) a device having a helical lamp disposed around the optical material, (b) a device having a elliptic reflection mirror disposed such that a lamp and the optical material are positioned at the two focal points thereof, respectively, and (c) a device with a pair of elliptic reflection mirrors disposed such that the optical material is located at the confocal point thereof with two lamps being located at the other focal points.
With the device (a), only part of the light from the helical lamp is utilized. Further, the lamp is apt to be broken upon collision with a hard thing. Moreover, it is not easy to exchange the lamp. The devices (b) and (c) become unavoidably large in size and complicated. The known devices (a)-(c) have also a problem that the space between the lamp and the optical material should be kept oxygen-free when vacuum ultraviolet rays are used.
It is an object of the present invention to provide a device which can emit condensed light from a lamp, condensed fluorescent or phosphorescent light generated by irradiation with a lamp or a laser beam generated by excitation with a flash lamp.
Another object of the present invention is to provide a device of the above-mentioned type which is simple and compact in construction, easy to handle and low in manufacturing costs.
In accomplishing the foregoing objects, there is provided in accordance with one aspect of the present invention a light emitting device comprising:
a lamp for producing light when supplied with electric current; and
an elongated, light transmissive, fluorescent or phosphorescent optical material having a portion disposed within said lamp and one end located outside said lamp,
so that said optical material emits fluorescent or phosphorescent light upon being excited by irradiation with the light of said lamp, with said fluorescent or phosphorescent light being transmitted to said one end.
In another aspect, the present invention provides a light emitting device comprising:
a lamp for producing light when supplied with electric current; and
an elongated, light transmissive optical material transparent to the light of said lamp and having a portion disposed within said lamp and one end located outside said lamp,
so that the light of said lamp entering said optical material is transmitted to said one end.
The present invention also provides a light emitting device comprising:
a lamp for producing light when supplied with electric current; and
an elongated, light transmissive, laser generating optical material having a portion disposed within said lamp and one end located outside said lamp,
so that said optical material emits a laser beam upon being excited with the light of said lamp, with said laser beam being transmitted to said one end.